When many devices are connected to a data bus, such as in a multi-media application, conflicts will occur where two devices request access to the bus at the same time. To resolve these conflicts, arbiters have been developed to grant bus access to the device having the highest priority. Thus, when two devices are in contention for the bus, the arbiter first gives access to the device with the higher priority of the two and subsequently gives access to the device with the lower priority.
In a system with such an arbiter, a device with a very high priority will get frequent access to the bus while a device with a low priority will get infrequent access to the bus. This can present a problem when the devices are assigned their priorities during system initialization or boot-up such that the relative priorities of the devices do not change over time. A situation can exist where a low priority device needs access to the bus in order to continue functioning but cannot obtain access because a high priority device which does not necessarily need access happens to be requesting bus access coincidentally. Thus, although the system is granting access on a priority basis, inefficiencies can result where low priority devices experience idle time or malfunction.